Push into your wall, not the open edge
An atari is also a steering wheel: the side you atari from decides which way the runner flees. Drive it toward the edge, where liberties run out, or toward your own thickness, where every step is wasted strength — never toward its friends or the open centre, which is a rescue. Before atariing, look one move past the contact: where will its last remaining liberty sit, and is that ground favourable to you? Here the wall stands on the right, so the atari must come from the left, herding White's escape straight into B(6,4). Atari direction is attack direction (Chapter 12) in miniature: always steer the opponent toward your strength.